money separator + zero support (not regex) | unity3d

using System;

namespace avstn.moneySeparator
{
    class Program
    {
        private static void Main(string[] args)
        {
            int numb;

            do
            {
                Console.WriteLine("Enter number");

                numb = int.Parse(Console.ReadLine());

                Console.WriteLine("Result: {0} \n", separateMoney(numb, '.'));
            }
            while (numb > 0);
        }

        private static string separateMoney(int numb, char sepSymb)
        {
            string money = numb.ToString();

            int blLen = 3;

            if (money.Length <= blLen)
                return money;

            string response = string.Empty;

            do
            {
                string a = money.Substring(money.Length - blLen, blLen);
                money = money.Substring(0, money.Length - blLen);

                response = string.Format("{0}{1}{2}", sepSymb, a, response);
            }
            while (money.Length > blLen);

            return string.Format("{0}{1}", money, response);
        }
    }
}